CORE LAB ONLY - SAMPLE PROCESSING. The HIV protease inhibitors are a new class of antiretroviral agents with potent activity. Indinavir, given to zidovudine-experienced patients in combination with zidovudine and lamivudine, reduced viral loads in about 85% of patients to less than 500 copies per milliliter for up to one year. This leaves at least 15% of patients who continue to have viral loads above 500 copies per milliliter despite the indinavir-containing combination regimen. The optimal therapy for a person on an indinavir-containing combination regimen whose experiences are abound in viral load or never experiences a decrease in viral load below 500 copies per milliliter is unknown. This study formally tests the activity of the soft gelatin capsule of saquinavir in combination with ritonavir or nelfinavir and combinations of delavirdine, and/or adefovir dipivoxil in a group of subjects with indinavir experience and significant viral load levels.